A number of devices have been utilized to externally compress blood vessels in various parts of the body to reduce or stop the flow of blood through said vessels in order to achieve post-procedure vascular hemostasis. Such devices generally find use in clinical settings, e.g. cardiac catheterization laboratories where minimally invasive procedures are performed on patients, e.g. catheterization of coronary arteries by means of vascular access using catheters inserted through sheaths placed into vascular puncture sites and arteriotomies. Such puncture sites are typically located in an artery close to the patient's skin surface, e.g. a femoral artery in the groin area or radial artery in the wrist area. At the end of these procedures when the catheters and sheath are to be withdrawn, devices that externally compress blood vessels are often used to achieve hemostasis at the puncture site and arteriotomy. Also used is manual compression, i.e. external compression applied by an operator's hands or fingers.
Sometimes used in conjunction with such external compression are hemostatic agents, which assist in achieving hemostasis of a puncture site. Examples of such hemostatic agents are powders, and “patches” or pads in various shapes, generally composed of: i) a chitosan or other polysaccharide such as a β-(1-4)-linked D-glucosamine (deacetylated unit) or N-acetyl-D-glucosamine, ii) thrombin, iii) calcium alginate, or iv) minerals such as kaolin or potassium ferrate. Applied to a puncture site and in contact with an amount of blood, these agents can assist in the formation of a clot to accelerate the time to hemostasis.
Several devices, which are known to the inventor, help achieve hemostasis in blood vessels of the forearm using mechanical and/or pneumatic means of applying compression over a blood vessel, for the purpose of allowing a clot to form, thereby enabling hemostasis and corollary cessation of bleeding. Features noted in this art are: i) the use of clamping or inflatable bladder mechanisms to selectively apply compression to those portions of the body surface overlying a target blood vessel and ii) the incorporation of features to gradually reduce compression and permit direct visual observation of a surface wound or puncture site leading to the target vessel.
The prior art teaches that compression applied externally, i.e. on the body surface and over a target blood vessel, slows the blood flow such that a clot can form so that normal hemostasis may occur. The prior art further teaches the value of: i) visual and physical access to the puncture or wound site on the body surface; ii) preferential and adjustable compression over a target vessel, so that arterial flow to or venous return from an extremity, for example a hand, are important attributes of a device having the purpose of achieving hemostasis following catheterization or other cannulation; iii) quickly releasing compression and removing the device from the patient; iv) enabling distal blood flow through adjacent blood vessels, for example, distal blood flow through the ulnar artery and venous return from the hand, while compression over the target vessel is applied; and, v) enabling distal blood flow through the target blood vessel while compression is applied to it.
The term “patent hemostasis” has been coined and was initially described by Samir Pancholy, MD in the PROPHET Study of 2007, where continued perfusion through the radial artery during the period in which external compression is applied for the purpose of achieving hemostasis at the arteriotomy and puncture site is required in order to reduce the incidence of chronic radial artery occlusion, a not-uncommon complication of radial access. He demonstrated that maintaining patency of the radial artery during the hemostasis period and adjusting compression to permit such patent hemostasis helps to avoid chronic radial artery occlusion.
Recently, medical discoveries (Bernat I, et al, “Efficacy and safety of transient ulnar artery compression to recanalize acute radial artery occlusion after transradial catheterization,” American Journal of Cardiology, 2011 Jun. 1; 107(11):1698-701. doi: 10.1016/j.amjcard.2011.01.056. Epub 2011 Mar. 23) regarding thrombosis resulting from accessing the radial artery for catheterization have shown an advantage to applying compression over the ulnar artery immediately post-procedure for patients in whom the radial artery is occluded, while avoiding bleeding from the radial puncture site. Achieving simultaneous compression of the ulnar artery during radial artery hemostasis in this fashion was performed using either a second device or applying manual compression (i.e. with the operator's fingers) over the ulnar artery. It's also expected that ulnar compression concomitant with compression over the radial artery for the purpose of achieving hemostasis will result in easier achievement of patent hemostasis in a substantial proportion of patients. Although many compression devices are available for compression of the radial artery there are none known to the inventor that can also simultaneously provide compression of the ulnar artery, which are available to clinicians.
A pneumatically-adjustable device called the TR Band marketed by Terumo, as described in U.S. Pat. No. 7,498,477 by Wada, utilizes a wrist-encircling strap that applies compression by means of two inflatable bladders, one of which directly underlies the other, both for the purpose of compressing only the radial artery. The TR Band is initially attached to the patient using hook and loop fastening after positioning the bladders over the radial artery puncture site; a syringe is then attached to a tube connected to both bladders and air is injected to expand the bladders, thereby applying compression over the puncture site to achieve hemostasis when the sheath is pulled from the vessel. Air can then be gradually withdrawn from the bladders to usually enable patent hemostasis, i.e. blood flow through the radial artery without any bleeding from the arteriotomy and puncture site. The TR Band has no bladder or other compression means to apply compression over the ulnar artery.
Additional attributes of the TR Band include the feature whereby compression over the radial artery during deployment, caused by inflation of the bladders, automatically reduces during deployment without action by the user, through material stretching or automatic release of some of the volume of air contained in the bladders. Anecdotal evidence suggests that this is an undesirable feature if the deflation is excessive, at least when patients on which it is deployed have been administered anti-coagulation medications and/or are hypertensive, both of which are not-uncommon occurrences in cardiac catheterization patients. Such automatic deflation sometimes has the effect of reducing compression to the point that bleeding occurs at the puncture because insufficient compression is applied to stop said bleeding.
Another pneumatically-adjustable compression device is described by Egnelov in U.S. Pat. No. 6,264,673, which is more commonly known by its trade name of Femostop. Comprising a single rigid beam to which two pneumatically inflatable pressure pads and a belt are attached, it is designed specifically to apply compression to either femoral arteries or femoral veins for the simultaneous bilateral compression of said arteries or veins for the purpose of simultaneously providing hemostasis to each of two bilaterally-located puncture sites, one in each artery or vein. Models are also available for puncture sites on only one side of the patient.
Other devices in common usage include the RadAR Vascular Compression Device as described by Niemeyer in abandoned U.S. Pat. Appl. No. 61/198,956. The RadAR device also applies adjustable compression, however such compression is modulated by mechanical and not pneumatic means. Another device is described by Niemeyer et al in pending U.S. patent application Ser. No. 14/227,160, where the adjustment means is achieved by a double ratcheting action. Another device is the HemoBand, described in U.S. Pat. No. 5,269,803 by Geary that discloses a strap that encircles the forearm with a pressure pad that applies compression over the vessel to prevent bleeding through the puncture. Other mechanically (as compared with pneumatically) operated devices that include a strap to prevent bleeding through a puncture site include: U.S. Pat. No. 4,182,338 to Stanulis; U.S. Pat. No. 4,005,709 by Laerdal; U.S. Pat. No. 3,954,109 by Patel; and U.S. Pat. No. 3,586,001 by Sanderson. Another device that includes a hemostat is the D-Stat Radial, from Vascular Solutions, Inc. Of these mechanical devices, only the Niemeyer devices enable easy adjustment, and none feature any compression means to provide simultaneous compression over the ulnar artery during radial artery compression.
Therefore, a need exists for an adjustable radial and ulnar compression wristband. Such a device is described in the U.S. Provisional Patent Applications No. 61/957,817 filed on Jul. 12, 2013 and No. 61/976,978 filed on Apr. 8, 2014 by Philip Benz, an inventor on this present non-provisional application.